1. Field of the Invention
The present invention relates to an oil applying roller working as an oil applicator. The oil applying roller according to the present invention may be used in contact with the surface of a fixing roller of an electrophotographic copying apparatus. The fixing roller means a heat roller or a pressure roller of an electrophotographic copying apparatus.
2. Description of the Prior Art
The Japanese Laid-Open Utility Model No. 73762/1984 discloses a tank type oil applying roller of a conventional type. As shown in FIG. 1, the tank type oil applying roller 200 comprises an aluminum pipe 201 provided in the middle of the tank type oil applying roller and having through holes 202 on its periphery surface, an integrated fibrous material 203 provided on the surface of the aluminum pipe 201, and a heat resistance integrated fibrous material 204 provided on the surface of the integrated fibrous material 203.
The tank type oil applying roller 200 has an applying oil 205 filled in the hollow of the aluminum pipe 201. The oil 205 impregnates through the through holes 202 formed on the aluminum pipe 201 to the outer integrated fibrous materials 203 and 204 by the capillarity. The tank type oil applying roller 200 is provided in contact with the surface of a fixing roller. The tank type oil applying roller 200 applies the oil 205 to the surface of the fixing roller by rotating, and thus prevents offset of the toner particles from the copy sheet to the fixing roll. Further, the tank type oil applying roller 200 removes and cleans stains adhered on the surface of the fixing roller.
When an electrophotographic copying apparatus has been left unused for a long period of time, the conventional tank type oil applying roller applies a large amount of oil to the surface of the fixing roller especially in the initial stage of reusing. Accordingly, there has occurred a problem on the deterioration of the oil preservation and a problem on the largely varying oil applying amount depending on the size of paper or copying modes such as single-copying mode and multi-copying mode. Further, the copying paper has been stained with the oil when the oil applying amount is too much, and furthermore the non-paper delivered portions of the fixing roller have caused the worsened oil stain.
More specifically, the oil is equally applied to the fixing roller in spite of the size of copying papers. When the copying papers of small size, i.e., B5 size are successively fed to execute multi-copying, the oil is gradually accumulated at the portion on the fixing roller not contacting with the B5 papers (This portion is referred to as non-paper delivered portion hereinafter). If the copying papers of large size, i.e., A4 size are fed for copying operation after the multi-copying of B5 size papers, the portion of the A4 size paper contacting with the non-paper delivered portion may be stained with the accumulated oil.